For example, Patent Document 1 mentions such a drill wherein:
front flanks providing a pair of front cutting ridges and a chisel edge by cross thinning, are formed at the front of the drill body; and
first and second flanks are formed on each front flank.
Patent Document 2 also mentions a drill wherein:
the front flanks comprise n flanks, namely, first to nth flanks (n≧3); and
coolant holes are open on each boundary between a flank and the subsequent flank, except on the boundary between first and second flanks.